Waterproofing Pipe Sleeve Application Guide The waterproofing pipe sleeve, also known as a wall penetration sleeve or penetration pipe, is generally suitable for structures where pipelines pass through walls and experience vibration or have strict waterproofing requirements. After local processing of the sleeve, a primer coat (including camphor oil or cold bottom oil) is applied to its outer wall. Waterproofing pipe sleeves are divided into rigid and flexible types. The main difference between them lies in their primary applications; flexible waterproofing pipe sleeves are mainly used in places with high requirements, such as civil defense walls and water pools, while rigid waterproofing pipe sleeves are typically used in basements and other pipeline installations requiring pipe架ing.